str1 = "Hello"
str2 = " World!"
str3 = ", Python"
str7 = "My name is Tom, age is 24, classmate is 24 grade"
str4 = str1.join(str2)  # 将str2每个字母折出来，拼接在str1
print(str4)

str5 = str3.split(",")  # 将字符串3中逗号做分隔符号，返回的结果是列表结果
print(str5)

str6 = str7.split(",")  # 将字符串7中逗号做分隔符号，返回的结果是列表结果
print(str6)
